1. Field of the Invention
This invention relates to drive control devices provided for vehicles having automatic transmission for changing gears in response to shift ranges.
2. Description of the Related Art
Generally, vehicles (e.g. cars) are equipped with automatic transmission for changing gears in response to shift ranges such as the non-running range and running range, each of which is appropriately selected by a driver. At a shift mode to change gears from the non-running range to the running range, a driver of the vehicle inevitably feels a start shock in running.
The vehicle equipped with the automatic transmission, which is disclosed by the paper of Japanese Patent Application, Publication No. Hei 5-118435, for example, operates as follows:
At a start mode, the shift range is changed from the neutral range (i.e., N range) to the drive range (i.e., D range). Therefore, oil pressure is applied to the clutch of the gear which is selectively engaged at the start mode, so that the clutch is put in an engaged state. Thus, drive force of the engine is transmitted to the wheels via the engaged gear at the start mode. Normally, the driver depresses the accel (or accelerator pedal) to start the vehicle after changing the gears from the N range to the D range.
In some case, there occurs a situation due to carelessness of the driver that the driver depresses the accelerator pedal in the N range but the drive changes gears from the N range to the D range while depressing the accelerator pedal. For instance, such a situation occurs as follows.
The driver does not take notice of a fact that the shift range is presently placed in the N range but watches another vehicle, parked in front of the driver's vehicle, to suddenly start running. In that case, the driver depresses the accelerator pedal in a fluster, then, the driver realizes that the present shift range is the N range, so that the driver changes over the shift range from the N range to the D range.
In the aforementioned situation, engagement of the clutch is made under a condition that the engine speed is high. So, there occurs a problem that an engagement shock becomes large. The technology disclosed in the aforementioned paper suffers from such a problem as well.